Electrophotographic copying system

ABSTRACT

An electrophotographic copying system comprising belt-shaped conveying unit which carries a light-sensitive paper and moves it along a closed path. Above the path is fixed a receptacle on which is placed an original to be copied. Between the receptacle and the light-sensitive paper is positioned a movable unit which houses an optical system and charging means. The unit is moved to provide exposure when the light-sensitive paper remains stationary. Upon termination of the exposure, the conveying unit moves the light-sensitive paper on which a latent image is formed through a developing unit, a transfer station and a cleaner unit in sequence. A transfer paper is supplied to the transfer station to effect the transfer of image from the light-sensitive paper, and is separated therefrom by a separation unit after the transfer paper has an image transferred thereto. The separated transfer paper is passed to a fixing unit in order to fix the transferred image.

[ Feb. 19, 1974 ELECTROPHOTOGRAPHIC COPYING SYSTEM [75] Inventors:Yasuhisa Matsuda; Kinya Amemiya;

Masao Monma; Koichi Endo; I-Iiroshi Nitanda, all of Tokyo, Japan [73]Assignee: Konishiroku Photo Industry Co.,

Ltd., Tokyo, Japan [22] Filed: Dec. 8, 1971 [21] Appl. No.: 205,966

Related US. Application Data ['63] Continuation of Ser. No. 13,668, Feb.24, 1970,

Primary Examiner-Robert P. Greiner Attorney, Agent, or Firm-Waters,Roditi, Schwartz & Nissan [57] ABSTRACT An electrophotographic copyingsystem comprising belt-shaped conveying unit which carries alightsensitive paper and moves it along a closed path. Above the path isfixed a receptacle on which is placed an original to be copied. Betweenthe receptacle and the light-sensitive paper is positioned a movableunit which houses an optical system and charging means. The unit ismoved to provide exposure when the light-sensitive paper remainsstationary. Upon termination of the exposure, the conveying unit movesthe light-sensitive paper on which a latent image is formed through adeveloping unit, a transfer station and a cleaner unit in sequence. Atransfer paper is supplied to the transfer station to effect thetransfer of image from the light-sensitive paper, and is separatedtherefrom by a separation unit after thetransfer paper has an imagetransferred thereto. The separated transfer paper is passed to a fixingunit in order to fix the transferred image.

19 Claims, 7 Drawing Figures PAIENTEDFEB x 91914 SHEU 3 0F 4 Fig.4

ELECTROPHOTOGRAPHIC COPYING SYSTEM CROSS RELATED APPLICATION Thisapplication is a continuation of copending application Ser. No. 13,668filed Feb. 24, 1970 and now abandoned. I

The. invention relates to an electrophotographic copyingsystem adaptedfor use in office copying, and

' has as an object the provision of a system which is convenient inoperation and inexpensively manufactured.

According tothe invention,.there is provided an electrophotographiccopying system which comprises a receptacle on which. is' placed an.original. to be copied, a belt-shaped conveying unit for alightasensitive paper, the unit having means. for loading thelight-sensitive paper thereon, exposure means movable between thelight-sensitive paper and said receptacle when the lightsensitive paperremains stationary, for projecting an image of the original onto thelight-sensitive paper, a developing unit, an image transfer unit and acleaner unit arranged in. turn. along the path of movementof thelight-sensitive paper, a transfer paper feeder for feeding a transferpaper to a transfer position in synchronism with said belt-shaped:light-sensitive paper conveying unit, a: transfer paper separation unitfor separating the transfer paper from. the light-sensitive paper afterthe transfer paper has mouedipast the transfer position, and

a fixing unit for fixing: the imagewhichv the transfer paper carriesafter it has beenseparatedifrom the lightsensitivepaper; i

For. better understanding. of. the invention, an embodimentthereofwill:be-described indetailbelbw with reference to: the drawings, inwhich:

FIG! 1. isas'chematic: i'llustrationtof one embodiment of the system:according to the invention,

FIG. 2: is a perspective: view of part of the system, showing the.loading; means for the; forward end of a light-sensitive. paper,

FIG. 3 isa view similar'to that ofFIG. 2, but showing theloadingmeansfor the rear'endlof the light-sensitive paper,

FIG. 4'is afrontview. ofthe. loading means for the. forward end. of thelight-sensitive. paper,

FIG. 5 is a perspective view of the transfer paper separation unit ofthe'system,

FIG. 6.:is a side elevation of a transfer station of the system,illustratingthe, transfer paper'separationunit in its raised position,and,

FIG. 7 is aviewsimilar to-that of FIG. 6,. but showing the transferpaper separation unit in its lowered position.

Referring tothe. drawings, and: more particularly to FIG. 1, thecopying, system includes an optical system comprising.parts designatedby numerals-.1 to 5. Specifically, numeral 1 denotes'a support frame forthe optical system, and.2an in-mirror-lens which comprises a rectangularprism and a lens and which acts to reverse the lateral relationship ofan image, that is, bringing the right'hand side; to the. left-hand sideand vice versa. Referencecharacter 3a. or 3b denotes a reflectingmirror, 4a lamp for illuminatingan original to be copied, and 5 adiaphragm forcontrolling the amount of light, the diaphragm 5' beingpivoted at 5a; The support frame 1 is attachedtomovable belts 6. Theoriginal to be copied is placed on a receptacleshown at 7 on the top ofthe system-iv The support frame 1 also carries a corona disch'arger 8 inits bottom. A pair of lightsensitive papers 9a and 9b are loaded ormounted on an endless belt 10 which runs around rotatable rollers 11aand 11b, the light-sensitive papers being detachably mounted on the belt10 as will be described later in further detail. Along the path ofmovement of the lightsensitive papers are disposed in turn a developingunit 12, a corona discharger 16 for transfer purpose, a transfer paperseparation unit 17 and a cleaner unit 25. A stack of transfer papers 13is stored in a container 14, and a rotatable roller 15 takes out thetransfer papers sheet by sheet. The taken out transfer paper is guidedby a guide plate 18 and fed by rollers 19a, 19b and 190 to a transferposition, where it is held in contact with the light-sensitive paper asthe latter moves with the belt. Thereafter the transfer paper isseparated from the light-sensitive paper by the transfer paperseparation unit 17, and is fed on feed belts 20 and'21, arranged incascade, to be displaced out of the system. Above the feed belt 21 islocated a fixing unit 22. In the present example, the unit 17 and feedbelts 20, 21 are arranged to perform special functions which will bemore fully described later.

FIG. 2 shows light-sensitive paper loading means which serves theloading or mounting of the forward endiofa light-sensitive paperindicated at 40 on the belt 10. The forward end of the light-sensitivepaper 40 is formed with a pocket as indicated at 40a, into which isinserted a core rod 41. Numeral 42 denotes a channelshaped metal fittingfixedly secured to the belt 10 and which receives and supports the corerod 41. The loading means for the rear end of the light-sensitive paper40 is shown in FIG. 3. The rear end of the lightsensitive paper 40 isalso formed with a pocket as indicated at 405, into which is insertedanother core rod 43. Plate members 44" and 45 are secured to the belt10. The plate member 45 is formed with an elongate slot 46 therein, anda support plate 47 has a guide pin 48 which extends into the slot 46.The support plate 47 is also provided with a channel-shaped support 49for carrying the core rod 43. A coiled tension spring 50 extends betweenthe support plate 47 and the plate member 44' for maintaining thelight-sensitive paper 40 taut or under tension. Numeral 51 denotes anoperating handle secured to the support plate 47 and which is used tooperate it when loading or unloading the lightsensitive paper 40.

Theloading of the light-sensitive paper onto the belt 10- takes place asfollows:

Initially the core rod 41 is inserted into the pocket 404 at the forwardend of the light-sensitive paper 40, and is mounted in thechannel-shaped metal fitting 42. Then the core rod 43 is inserted intothe pocket 40b at therear end of the light-sensitive paper 40, and whilepulling the support plate 47 to the left, as viewed in FIG. 3, againstthe action of the spring 50 by manually holding the handle 51, the corerod 43 is engaged in place within the channel-shaped metal fitting 49.The loading of the light-sensitive paper must be carried out in a mannersuch that the light-sensitive paper is always loaded in a definiteposition which is correctly estab lished relative to other parts of thesystem. This is achieved by a mechanism shown in FIG. 4.

Referring to FIG. 4, on the belt 10 is secured a plate 52 which isformed with a clicking recess 53. Another plate 54 fixedly attached to astationary part of the system is formed with a clicking aperture 55 at aposition which allows its alignment with the recess 53. In this apertureis placed a clicking ball 57 that is held in position by a leaf spring56. The mechanism just described constitutes a click device, andoperates as a detent to hold the belt 10 against motion momentarily whenthe light-sensitive paper is loaded onto the belt 10. The belt 10 isprovided with a number of perforations which are engaged in turn bysprocket pins (not shown) provided on the rollers 11a and 11b fordriving the belt. While loading means for the forward and rear ends ofthe light-sensitive paper are shown only for one side of thelight-sensitive paper, it should be understood that corresponding meansare also provided on the other side.

FIGS. to 7 show the detailed construction of the transfer paperseparation unit 17. A suction box 70 is formed with several elongateslots 71 (only one being shown) for suction of the air. Severalperforated belts 72 extend around the suction box 70 and rollers 73 and74. The roller 73 is a drive roller, and a tensioning roller 75 ispositioned intermediate the rollers 73 and 74.

The belts 72 are arranged around the suction box 70 so as to overly theelongate slots 71 therein, and their position is controlled by aplurality of flanges 76 on the roller 73. The suction box 70 and therollers 73, 74 and 75 are carried at their opposite ends by supportplates 77a and 77b which are pivoted at 78 to further support plates 79aand 79b. At their freely movable end, the support plates 77a and 77b areconnected to the plates 79a and 79b through springs 80 and are providedwith cam followers 81a and 81b, respectively, which cooperate withrotary cams 82a and 82b which are mounted on a shaft extending throughthe plates 79a and 79b. These cams are driven in synchronism with thebelt carrying the light-sensitive paper. A suction duct 83 communicateswith the interior of the suction box 70, which is divided by a partitionwall 84 into compartments A and B. The communication is such that theduct 83 communicates with the compartment A to a greater degree thanwith the compartment B, so that the resulting suction through theelongate slots 71 is stronger in the part thereof which is positionedover the compartment A than in the part positioned over the compartmentB. The arrangement is such that the transfer paper is subjected to astrong suction while in contact with the light-sensitive paper toprovide a satisfactory separation therefrom, and is subsequentlysubjected to a lesser suction, after separation, to be further conveyedunder minor suction.

The feed belt is operated at a speed which is less than the feedingspeed of the separation unit 17, and the feed belt 21 is designed toconvey the transfer paper at a speed which is even more reduced thanthat ofthe belt 20. However, this is not critical, and the feed belt 21can be operated at a speed which is equal to or greater than that of thebelt 20, as far as sufficient fixing can be assured. This isaccomplished by connecting their respective drive rollers 23 and 24 witha drive shaft (not shown) through differential gearing ratios, which canbe arranged in any conventional manner and therefore is not describedhere in detail.

The system operates as follows:

The light-sensitive paper 9a is loaded as explained previously. The belt10 remains stationary while the light-sensitive paper 9a is uniformlycharged and then imagewise exposed by the movement of the optical systemframe 1 in the direction indicated by the corresponding arrow. The lamp4 and the corona discharger 8 are energized during this movement. Thecharging followed by imagewise exposure produces a latent electrostaticimage on the light-sensitive paper 90. The termination of the chargingand exposure is indicated by the position of the frame ,1 shown in chainlines, nd thereafter the belt 10 starts to move in the directionindicated by the corresponding arrow. During the movement of the belt10, the light-sensitive paper 9a passes by the developing unit 12,transfer corona discharger 16, separation unit 17 and cleaner unit 25 insequence. While the belt 10 moves, the frame 1 is moved in the oppositedirection to'return it to its original position shown in solid lines. Atransfer paper 13 is supplied and fed in synchronism with the movementof the belt 10, and is superimposed with the light-sensitive paper atthe transfer position. After transfer of the image, the transfer paperis separated from the light-sensitive paper by the separation unit 17,and is conveyed on the belts 20 and 21 to be subjected to the fixationof the transfered image by thefixing unit 22, whereafter it is displacedout of the system.

As mentioned above, the belts 20 and 21 operate at reduced speeds. Thismeans that the movement of the transfer paper is slow in passing throughthe fixing unit 22. As a result, the transfer paper 13 is exposed toheat over a prolonged period, and hence the fixing unit 22 can operateefficiently. This allows that a fixing unit having a relatively smalloutput as compared with the copying rate can be satisfactorily used toprovide sufficient fixing function. This improvement concerning thefixing unit is enabled by the fact that light-sensitive papers 9a and 9bare loaded on the belt 10 with a certain spacing therebetween, a similarspacing being provided between successive transfer papers whereby thecopying process can be continuously run without interruption of themovement of the belt 10. Hence, a reduction of the speed of the transferpaper subsequent to the transfer step does not result in an overlappingof successive transfer papers. In one specific example the belt 10 had,for instance, a total length of 1,350 mm, and a pair of light-sensitivepapers of B-4 size (364 X 257 mm) were loaded lengthwise on this belt atsymmetrical positions. The belt 10 was driven at mm/sec. A reduction ofthe speed of the transfer paper at the fixing unit 22, that is, thespeed of movement of the belt 21, to 55 mm/sec. did not produce anoverlapping of successive transfer papers in a continuous copying run.In this example, the belt 20 was driven at 90 mm/sec. When the transferpaper moves across the space between the separation unit 17 and the belt20 or between the belts 20 and 21, it merely slips to accommodate forthe differential speeds.

As the forward end of the light-sensitive paper 9a moves over theseparation unit 17, the suction box 70 is lowered to the position shownin FIG. 7, thereby allowing the free passage of parts such as core rod41 of the loading means for the forward end of the lightsensitive paper.This is controlled by the cams 82a and 82b which rotate in synchronismwith the belt 10 and which have a raised portion situated so as to movethe suction box 70 downward through cam followers 81a and 81b when theforward end of the light-sensitive paper 9a has moved past the transferposition. A similar provision is made for allowing free passage of therear end of the light-sensitive paper 9a over the separation unit 17.The separation unit 17 is shown in its raised position in FIG. 6.

As described above, the light-sensitive paper is loaded on thebelt to bedriven thereby and is subjected to a transfer procedure. This reducesthe manufacturing cost as compared with the prior art systems used inxerography which employ a master plate in the form of a drum. Inaddition, the exposure is carried out with the light-sensitive paperstationary, which assures an improved quality and particularly improvedresolution of copy obtained. A copy made by the use of the transfertechnique can be obtained on a conventional paper which has not beensubjected to special treatment, and this represents a further advantagecompared with prior artcopying systems. A

What is claimed is:

1. An electrophotographic copying system comprising a light sensitivesheet adapted for receiving an electrostatic charge and for forming anelectrostatic image upon being exposed to a light image, said sheetbeing provided with at least one'transverse pocket, means including anendless belt toconvey said sheet through exposure and developingstations repeatedly and means detachably connecting the sheet to thefirst said means and including a bar coupled to the belt and extendingthrough said pocket.

2. An electrophotographic copy system comprising a displaceable belt, alight sensitive sheet, means detachably connecting the sheet to saidbelt, means to give the sheet an electrostatic charge, said belt beingadapted to displace the sheet through exposure and transfer stations,means to expose the sheet to an image in said exposure station, means toapply a developing substance to the sheet after the sheet has beenexposed and transfer means to apply a transfer sheet to the lightsensitive sheet to remove the developing substance from the latter andto transfer the image to the transfer sheet in said transfer station,said means which-detachably connects the sheet to the belt comprisingmeans covered by said sheet and extending laterally therefrom fordetachable attachment to said belt laterally'of the sheet and outsidethe path of travel thereof.

3. A system as claimed in claim 2 comprising means to drive said beltwith intermittent movement, said belt holding the light sensitive sheetstationary for exposure to said image. i

4. A system as claimed in claim 2 wherein the transfer means includes atleast one endless belt bringing the transfer sheet into engagement withthe light sensitive sheet and drawing the transfer sheet away from thelight sensitive sheet.

5. A system as claimed in claim 2 wherein the means to give the lightsensitive sheet a charge is displaceable along the latter said sheet.

6. A system as claimed in claim 2 wherein the means to apply saiddeveloping substance physically engages the light sensitive sheet. 7

7. A system as claimed in claim 2 comprising fixing meansfor fixing thedeveloped image on the transfer sheet.

8. An electrophotographic copy system comprising a displaceable belt, alight sensitive sheet, means detachably connecting the sheet to saidbelt, means to give the sheet an electrostatic charge, said belt beingadapted to displace the sheet through exposure and transfer stations,means to expose the sheet to an image in said exposure station, means toapply a developing substance to the sheet after the sheet has beenexposed and transfer means to apply a transfer sheet to the lightsensitive sheet to remove the developing substance from the latter andto transfer the image to the transfer sheet in said transfer station,said light sensitive sheet being provided with a pocket at each endthereof, said means detachably connecting the sheet to the beltcomprising a rod engaged in each pocket and extending laterallytherefrom and means for securing said rod to said belt at locationslaterally spaced from the sheet and outside the path of travel thereof.

9. A system as claimed in claim 8 wherein the rods are loosely supportedin the respective pockets.

1() An electrophotgraphic copying system comprising a light sensitivesheet adapted for receiving an electrostatic charge and for forming anelectrostatic image upon being exposed to a light image, means includingan endless belt to convey said sheet through exposure and developingstations repeatedly and means detachably connecting the sheet to theendless belt including means .covered by said sheet and extendinglaterally therefrom for detachable attachment to said belt-laterally ofthe sheet and outside the path of travel thereof.

11. An electrophotographic copying system comprising a light sensitivesheet adapted for receiving an electrostatic charge and for forming anelectrostatic image upon being exposed to a light image, said sheethaving opposite ends with a pocket at each end, means including anendless belt to convey said sheet through exposure and developingstations repeatedly and means detachably connecting the sheet to thebelt including a rod engaged in each pocket and extending laterallytherefrom and means for securing said rod to said belt at locationslaterally spaced from the sheet and outside the path of travel thereof.

12. A system as claimed in claim 11 wherein the rods are looselysupported in the respective pockets.-

13. An electrophotographic copying system comprising a receptacle onwhich is placed an original to be copied, a belt-shaped conveying unitfor holding a light-sensitive paper stationary in a first phase and fordisplacing the light-sensitive paper along a path in a second phase, theunit including means for detachably loading the light-sensitive paperthereon, a unit for charging the light-sensitive paper with a coronadischarge before exposure of the paper, exposure means movable betweenthe light-sensitive paper and said receptacle, with the light-sensitivepaper remaining stationary, for projecting an image of the original ontothe light-sensitive paper, a developing unit, an image transfer unit anda cleaner unit arranged in sequence along the path of movement of thelightsensitive paper, a transfer paper feeder for feeding a transferpaper to a transfer position in synchronism with said belt-shapedlight-sensitive paper conveying unit, a transfer paper separation unitfor separating the transfer paper from the light-sensitive paper afterthe transfer paper has moved past the transfer position, and a fixingunit for fixing the image which the transfer paper carries after it hasbeen separated from the light-sensitive paper, said conveying unit beingthe form of an endless belt running, at least in part, along a flatpath, whereby the light-sensitive paper can be loaded onto the belt in aflat configuration, and in which a pair of light-sensitive papers,including the first said light-sensitive paper, are loaded on theendless belt with a spacing between the papers, said papers beingalternatively subjected to said exposure means.

14. An electrophotographic copying system according to claim 13,comprising and in which said separation unit is associated with at leastone additional conveyor means on which the transfer paper is carried,said additional conveyor means being adapted to be driven at a selectedspeed less than the speed at which the transfer paper is conveyed by theseparation unit, said selected speed being related to the spacingbetween the pair of light-sensitive papers loaded on the belt so thatthe system can be continuously run without causing an overlapping ofsuccessive transfer papers to occur on said additional conveyor means.

15. An electrophotogr aphic copying system accord ing .to claim 14, inwhich said additional conveyor means comprises a pair of first andsecond endless belts arranged in cascade manner from the separationunit; said fixing unit being positioned over the second endless belt,said first endless belt being driven at a first speed which is less thanthe speed at which the transfer paper is conveyed by the separationunit, said second endless belt being driven at a second speed less thansaid first speed.

16. An electrophotographic copying system according to claim 14,comprising and in which said separation unit is associated with at leastone additional conveyor means, said additional conveyor means beingadapted to be'driven at a speed which is less than the speed at whichthe transfer paper is conveyed by the separation unit.

17. A system as claimed in claim 13 wherein said means which detachablyconnects the light sensitive paper to the belt-shaped conveying unit Icomprises means covered by said light sensitive paper and extendinglaterally therefrom for detachable attachment to said unit laterally ofthe light sensitive paper and outside the path of travel thereof.

18. A system as claimed in claim 17 wherein said light sensitive paperis provided with a pocket at each end thereof, said means detachablyconnecting the paper to the belt-shaped unit comprising a rod engaged ineach pocket and extending laterally therefrom and means for securingsaid rod to said belt-shaped unit at locations laterally spaced from thepaper and outside the path of travel thereof.

19. A system as claimed in clain 18 wherein the rods are looselysupported in therespective pockets.

* =l l l

1. An electrophotographic copying system comprising a light sensitive sheet adapted for receiving an electrostatic charge and for forming an electrostatic image upon being exposed to a light image, said sheet being provided with at least one transverse pocket, means including an endless belt to convey said sheet through exposure and developing stations repeatedly and means detachably connecting the sheet to the first said means and including a bar coupled to the belt and extending through said pocket.
 2. An electrophotographic copy system comprising a displaceable belt, a light sensitive sheet, means detachably connecting the sheet to said belt, means to give the sheet an electrostatic charge, said belt being adapted to displace the sheet through exposure and transfer stations, means to expose the sheet to an image in said exposure station, means to apply a developing substance to the sheet after the sheet has been exposed and transfer means to apply a transfer sheet to the light sensitive sheet to remove the developing substance from the latter and to transfer the image to the transfer sheet in said transfer station, said means which detachably connects the sheet to the belt comprising means covered by said sheet and extending laterally therefrom for detachable attachment to said belt laterally of the sheet and outside the path of travel thereof.
 3. A system as claimed in claim 2 comprising means to drive said belt with intermittent movement, said belt holding the light sensitive sheet stationary for exposure to said image.
 4. A system as claimed in claim 2 wherein the transfer means includes at least one endless belt bringing the transfer sheet into engagement with the light sensitive sheet and drawing the transfer sheet away from the light sensitive sheet.
 5. A system as claimed in claim 2 wherein the means to give the light sensitive sheet a charge is displaceable along the latter said sheet.
 6. A system as claimed in claim 2 wherein the means to apply said developing substance physically engages the light sensitive sheet.
 7. A system as claimed in claim 2 comprising fixing means for fixing the developed image on the transfer sheet.
 8. An electrophotographic copy system comprising a displaceable belt, a light sensitive sheet, means detachably connecting the sheet to said belt, means to give the sheet an electrostatic charge, said belt being adapted to displace the sheet through exposure and transfer stations, means to expose the sheet to an image in said exposure station, means to apply a developing substance to the sheet after the sheet has been exposed and transfer means to apply a transfer sheet to the light sensitive sheet to remove the developing substance from the latter and to transfer the image to the transfer sheet in said transfer station, said light sensitive sheet being provided with a pocket at each end thereof, said means detachably connecting the sheet to the belt comprising a rod engaged in each pocket and extending laterally therefrom and means for securing said rod to said belt at locations laterally spaced from the sheet and outside the path of travel thereof.
 9. A system as claimed in claim 8 wherein the rods are loosely supported in the respective pockets.
 10. An electrophotographic copying system comprising a light sensitive sheet adapted for receiVing an electrostatic charge and for forming an electrostatic image upon being exposed to a light image, means including an endless belt to convey said sheet through exposure and developing stations repeatedly and means detachably connecting the sheet to the endless belt including means covered by said sheet and extending laterally therefrom for detachable attachment to said belt laterally of the sheet and outside the path of travel thereof.
 11. An electrophotographic copying system comprising a light sensitive sheet adapted for receiving an electrostatic charge and for forming an electrostatic image upon being exposed to a light image, said sheet having opposite ends with a pocket at each end, means including an endless belt to convey said sheet through exposure and developing stations repeatedly and means detachably connecting the sheet to the belt including a rod engaged in each pocket and extending laterally therefrom and means for securing said rod to said belt at locations laterally spaced from the sheet and outside the path of travel thereof.
 12. A system as claimed in claim 11 wherein the rods are loosely supported in the respective pockets.
 13. An electrophotographic copying system comprising a receptacle on which is placed an original to be copied, a belt-shaped conveying unit for holding a light-sensitive paper stationary in a first phase and for displacing the light-sensitive paper along a path in a second phase, the unit including means for detachably loading the light-sensitive paper thereon, a unit for charging the light-sensitive paper with a corona discharge before exposure of the paper, exposure means movable between the light-sensitive paper and said receptacle, with the light-sensitive paper remaining stationary, for projecting an image of the original onto the light-sensitive paper, a developing unit, an image transfer unit and a cleaner unit arranged in sequence along the path of movement of the light-sensitive paper, a transfer paper feeder for feeding a transfer paper to a transfer position in synchronism with said belt-shaped light-sensitive paper conveying unit, a transfer paper separation unit for separating the transfer paper from the light-sensitive paper after the transfer paper has moved past the transfer position, and a fixing unit for fixing the image which the transfer paper carries after it has been separated from the light-sensitive paper, said conveying unit being the form of an endless belt running, at least in part, along a flat path, whereby the light-sensitive paper can be loaded onto the belt in a flat configuration, and in which a pair of light-sensitive papers, including the first said light-sensitive paper, are loaded on the endless belt with a spacing between the papers, said papers being alternatively subjected to said exposure means.
 14. An electrophotographic copying system according to claim 13, comprising and in which said separation unit is associated with at least one additional conveyor means on which the transfer paper is carried, said additional conveyor means being adapted to be driven at a selected speed less than the speed at which the transfer paper is conveyed by the separation unit, said selected speed being related to the spacing between the pair of light-sensitive papers loaded on the belt so that the system can be continuously run without causing an overlapping of successive transfer papers to occur on said additional conveyor means.
 15. An electrophotographic copying system according to claim 14, in which said additional conveyor means comprises a pair of first and second endless belts arranged in cascade manner from the separation unit, said fixing unit being positioned over the second endless belt, said first endless belt being driven at a first speed which is less than the speed at which the transfer paper is conveyed by the separation unit, said second endless belt being driven at a second speed less than said first speed.
 16. An electrophotographic copying system according to claim 14, comprisiNg and in which said separation unit is associated with at least one additional conveyor means, said additional conveyor means being adapted to be driven at a speed which is less than the speed at which the transfer paper is conveyed by the separation unit.
 17. A system as claimed in claim 13 wherein said means which detachably connects the light sensitive paper to the belt-shaped conveying unit comprises means covered by said light sensitive paper and extending laterally therefrom for detachable attachment to said unit laterally of the light sensitive paper and outside the path of travel thereof.
 18. A system as claimed in claim 17 wherein said light sensitive paper is provided with a pocket at each end thereof, said means detachably connecting the paper to the belt-shaped unit comprising a rod engaged in each pocket and extending laterally therefrom and means for securing said rod to said belt-shaped unit at locations laterally spaced from the paper and outside the path of travel thereof.
 19. A system as claimed in clain 18 wherein the rods are loosely supported in the respective pockets. 